Is it permissible for me to return to my country to visit my family with my child due to my mother's health condition, knowing that my husband cannot return with me?

The basic principle is that it is impermissible for a woman to travel without a mahram, due to the prohibition stated in the Sunnah and the potential for trials and dangers that may result from such travel. This is an obligation whenever it is possible to fulfill it. However, if there is a compelling necessity and no mahram is available, then there is no blame in traveling without a mahram at that time, provided that necessary precautions are taken for her safety. It is obligatory to return to the lands of Islam if there is no necessity to reside in the lands of disbelief.